Handy Tips #1- Floor Prep
We plan to run a few "handy tips" blogs every now and then for all you DIY'ers out there wanting to get stuck into converting parts or all of your van. This is also a way to show our customers how their vans have been completed.
(please note that this is offered as advice and DCCampers take no responsibility for misinterpreted information, these are just bite sized bits of information and NOT instructions. If you wish to recieve further advice please do not hesitate to contact us)
So to kick off, as I see many times the question of best practices for lining the floor in preperation for a conversion.
This is based on a VW T5 floor but you will get the general idea for most other vans.
The floors of a van (certainly a T5) will often have raised ribs which tend to be pressed in the spans of the floor that are between chassis beams. Along the spans where the chassis points are the floor level drops, in some cases for a large part of the floor. If you were to just place some ply down onto a standard floor the chances of flex in your new ply floor is very high, especially when you are considering attaching or bolting down items of a conversion to the floor.
Initially you might find that the ply is perfectly fine, however over time the timber will start to loose its strength and eventualy the floor will start to dip and move.
To overcome this issue we fill the gaps with bocks of ply wood which bring these gaps up level with the ribs giving a lot more stable platform for your new floor.
Using 9mm external grade hardwood plywood we cut out blocks to fit the gaps making sure not to over size them so to cause any un-wanted raised sections. The Picture below shows these blocks cut and ready to fit.
The next point has had many opinions on forums and is always up for debate, I refer to screwing the ply floor down. 9 times out of 10 on a standard panel van (even direct from VW) a ply floor will likely be screwed straight through to the metal work using self taping screws, if you look underneath the van these literally just poke through the floor. Many would expect this to inscrease the risk of water ingress but more likely the chance of rust build up due to the screws opening up a hole which is not treated. If Im honest the amount of floors we have lifted we have never seen evidence of rust due to this method! however we are not about to start tempting fate so we fit the floors using the following method.
Once the old floor (if fitted and assuming its a ply floor) is lifted we treat each hole made from the screws with a rust inhibiting paint and then fill them with a blob of Sikaflex 221, this stops any possible water ingress now that the screw has been removed and will not be replaced.
Having cut the Ply blocks from the 9mm ply we bond these blocks to the floor using a Sikaflex (252 is great for structural appliances but tigerseal or other bonding adhesives would work). Ensure the floor is clean from all dirt and you apply some Etching primer to the area's you plan to apply the bond to.
Press the blocks down into place and leave them to dry for a number of hours (refer to the manufacterers reccommendations for drying times for the particular adhesive you are using) we usually fit these last thing on a day so that they have over night to dry out, do not try to attach the floor to the blocks when the adhesive is still wet as they will likely move or lift.
Once dry now is the time to insulate the floor however you wish, many silent coat the floor some don't, the floor can't really resonate much so we don't tend to silent coat the floors but can do as an option or if requested, we do however put a layer of insulation down to help improve the thermal properties of the floor.
Now its time to lay your new ply floor, we use 12mm external grade hardwood ply. The floor is most likely to get wet hence the reason for the external grade but there is no need to go to the expense of putting marine ply in as external ply is more than enough for the job.
At this stage is is worth measuring and noting where the ply blocks are located as you won't know where they are once the ply floor is down, it is these blocks that you bonded to the floor that you will need to screw the new ply floor onto. Once the ply floor is cut out and in place proceed to screw the floor down to secure it in place. Note the screw sizes as you don't want to be going through the floor after all this work, we use 4.0 x 20mm screws.
So there we have it! yes more time consuming than just screwing the floor down but this will give you a solid base throughout the entire floor space without bounce etc.
If you are using 12mm ply and are putting a thin carpet or Altro floor covering down the side step you will need is a Kombi step and then which ever Threshold plastic you wish to use at the rear (we use the full width ones as it finishes the floor off nicely.
Our floor preperation packages are put together to include the whole process as outlined above and include a brand new Kombi side step and Rear Threshold (full width to suit either barn door or tailgate doors), please contact us for more information or an estimate.
We might actually start selling ply floor kits complete with the ready cut 9mm ply batons if there is enough interest.
Happy to help with any advice if you have any further questions.